1. Field of the Invention:
The present invention relates to a takeup motion control device for varying the speed of winding up a woven fabric periodically or according to a desired speed pattern.
2. Description of the Prior Art:
Woven fabric takeup movement in a loom has to be effected in synchronism with the operation of the loom. The rotative power for operating the loom is normally reduced in speed so as to be available as rotative power for a takeup roll.
Weft yarn as it is interwoven with warp yarn is beaten by a reed up against the fell. The density of weft yarn picks inserted is dependent on the speed of winding up the fabric as it is successively woven. Therefore, the weft yarn density tends to vary as the speed of winding up the woven fabric varies.
Japanese Laid-Open Utility Model Publication No. 53-69577 discloses that in weaving a pile fabric, the weft yarn density can be varied in a pile fabric portion and other woven fabric portions by selecting one of two gear ratios for a takeup motion. With this prior art, however, the gear ratios cannot continuously be changed, and hence it is almost impossible to vary the weft yarn density continuously or periodically according to a desired repetitive pattern.